The present invention relates generally to systems and methods for locating sparks in electrostatic precipitators.
An electrostatic precipitator (ESP) removes particles from a flowing gas (such as air) using the force of an induced electrostatic charge. ESPs act as filtration devices that minimally impede the flow of gases and can easily remove fine particulate matter such as dust and smoke from the air stream. A typical ESP includes a row of cathodes disposed between large flat metal collection plates. The cathodes and the plates are typically applied with a high voltage of several thousand volts. The gas to be purified of fine particulate matter is flowed through the ESP near the cathodes. The high voltage ionizes the air around the cathodes. The gas stream flows through the spaces between the cathodes and then dust or particles (fine particulate) gets collected on the collection plates.
The fine particulate collection efficiency within a respective ESP is dependent on the field intensity that is proportional to the voltage applied between the cathodes. Thus, in order to efficiently collect fine particulate or dust, it is of utmost importance to maintain the applied voltage as high as possible. However, the voltage is limited by the phenomena of sparking that occurs more and more frequently as the electric field strength, temperature of the gas, humidity, or number of fine particulate or dust particles in the gas is increased. The composition of the gas and the resistivity of the fine particulate also have a major affect on the sparking voltage. Each time a spark occurs, the voltage across the ESP falls sharply and then, after the spark is extinguished, recovers to its original value. If the applied voltage is increased, the sparking rate is increased. ESP sparks in the cathodes, thus, result in lower operating voltage and hence reduced performance. Thus, it is useful not only to detect the existence or initiation of the sparks in an ESP but also to determine the location of the sparks.
Conventional methods of locating the sparks include manual viewing of sparks through glass, which viewing can be a challenge due to the large amount of dust that is typically present in ESPs. Such a process is time consuming and can only be done offline.
Thus, there is a need for a method and a system that detects and locates sparks within an ESP during operation to avoid excessive wear and tear, and improve the overall operability of an ESP.